I. Field of the Invention
The present invention generally relates to the field of fluid cylinders and, in particular, the present invention is concerned with fluid cylinders having a plurality of piston rods. More specifically, the present invention is concerned with an hydraulic press utilizing a cylinder with a plurality of piston rods for opening and closing a die on a workpiece.
II. Description of the Prior Art
Fluid cylinders having a plurality of piston rods have been known for a number of years. The multiple rod cylinders known in the art have been employed in brake mechanisms, baling machines, hydraulic machinery, and steam engines. All of the multiple rod cylinders known in the art employ a fixed cylinder with a movable piston and piston rods. The present invention, as will be described subsequently, employs fixed rods and a fixed piston with a cylinder that moves along the rod and pistons to perform work. Examples of multiple rod cylinders in the prior art are disclosed in U.S. Pat. Nos. 532,529; 699,936; 751,997; and 2,308,889. These patents are relevant to the Applicant's invention in that they represent the closest prior art utilizing fluid cylinders with a plurality of piston rods.